This invention concerns a device for braking a weft thread in a weaving machine. The device can be used in all types of weaving machines, but is particularly intended for rapier weaving machines.
It is known that in modern, high-speed rapier weaving machines the weft threads must be inserted into the shed in a controlled manner, in other words, each weft thread must be braked or released at the right moments and during particular periods of time in the weft insertion cycle. During the insertion movement of the grippers, on the one hand the braking must be kept to a minimum, both when the weft threads are being accelerated and during their rapid travel, in order to limit the tension in the weft thread and so prevent weft breaks. On the other hand, when the rate of travel of the grippers and of the weft thread is decelerating, and during the standstill of the weft thread, the weft thread must be braked in order to keep it taut and prevent weaving faults, or in order to keep the thread in a desired position.